I took a look around in at aliexpress and decided to order another shield. Here is what I got now:

The one on the left is the new „shield“, the one on the right is my well known „shiald“. Apart from a few visible differences (color, maintenance pin header, different ESP8266 version), these are the differences I found so far in their functionality:

Scenario

Shield

Shiald

Wires to the debug port, switches off

works as expected

works as expected

Wires to the debug port, switches 1+2 on

doesn’t work(?)

works as expected

Wires to the debug port, switches 3+4 on

ESP can be flashed

ESP can be flashed

Shield mounted on Arduino Uno, switches off

no connection between shield and Arduino. Serial Monitor/Flashing the Arduino does NOT work anymore

no connection between shield and Arduino. both work independently

Shield mounted on Arduino Uno, switches 1+2 on

no connection between shield and Arduino. Serial Monitor/flashing the Arduino does NOT work anymore

shield is connected to the Arduinos hardware serial. Communication works fine

web interface is very slow/unavailable sometimes. Connection to WiFi networks is doesn’t work sometimes

All in all, I’d highly recommend NOT to buy any of those shields. Their design seems to be flawed. If you still want to buy it anyway, I’d recommend the „shield“ variant. Even if it behaves more stupid than the „shiald“, it seems to provide more stable WiFi. Just bend pins 0 and 1 when attaching it to the Arduino and do the wiring manually as described in my other article.In case your project is flexible enough and you need WiFi: Just use the something like a NodeMCU instead of the Arduino. You can still program it using the Arudino IDE, but it has the WiFi build in and way cheaper than the shield (or even the Arduino).

I have also seen a Version 0.9 of this shield in some shops, but I am not willing to invest more time and money in crappy hardware for scientific reasons 😉 . If someone has some experience with it, I’d be happy to read about it in the comments.